我实现了一个解析一些URI模式的路由器类，以便正确地路由到控制器。
假设遵循简单的测试用例和我的期望
~/erlang_programs/my_gun$ gmake run
gmake[1]: Entering directory '/Users/7stud/erlang_programs/my_gun/deps/gun'
gmake[2]: Entering directory '/Users/7stud/erlang_programs/my_gun/deps/cowlib'
gmake[2]: Leaving directory '/Users/7stud/erlang_programs/my_gun/deps/cowlib'
gmake[2]: Entering directory '/Users/7stud/erlang_programs/my_gun/deps/ranch'
gmake[2]: Leaving directory '/Users/7stud/erlang_programs/my_gun/deps/ranch'
GEN rebar.config
gmake[1]: Leaving directory '/Users/7stud/erlang_programs/my_gun/deps/gun'
DEPEND my_gun.d
ERLC my.erl
APP my_gun
===> Starting relx build process ...
===> Resolving OTP Applications from directories:
/Users/7stud/erlang_programs/my_gun/ebin
/Users/7stud/erlang_programs/my_gun/deps
/Users/7stud/.evm/erlang_versions/otp_src_19.2/lib/erlang/lib
/Users/7stud/erlang_programs/my_gun/apps
/Users/7stud/erlang_programs/my_gun/_rel
===> Resolved my_gun_release-1
===> rendering builtin_hook_status hook to "/Users/7stud/erlang_programs/my_gun/_rel/my_gun_release/bin/hooks/builtin/status"
===> Including Erts from /Users/7stud/.evm/erlang_versions/otp_src_19.2/lib/erlang
===> release successfully created!
===> tarball /Users/7stud/erlang_programs/my_gun/_rel/my_gun_release/my_gun_release-1.tar.gz successfully created!
Exec: /Users/7stud/erlang_programs/my_gun/_rel/my_gun_release/erts-8.2/bin/erlexec -boot /Users/7stud/erlang_programs/my_gun/_rel/my_gun_release/releases/1/my_gun_release -mode embedded -boot_var ERTS_LIB_DIR /Users/7stud/erlang_programs/my_gun/_rel/my_gun_release/lib -config /Users/7stud/erlang_programs/my_gun/_rel/my_gun_release/releases/1/sys.config -args_file /Users/7stud/erlang_programs/my_gun/_rel/my_gun_release/releases/1/vm.args -pa -- console
Root: /Users/7stud/erlang_programs/my_gun/_rel/my_gun_release
/Users/7stud/erlang_programs/my_gun/_rel/my_gun_release
heart_beat_kill_pid = 38883
Erlang/OTP 19 [erts-8.2] [source] [64-bit] [smp:4:4] [async-threads:10] [hipe] [kernel-poll:false]
=PROGRESS REPORT==== 10-Jul-2017::18:04:38 ===
supervisor: {local,sasl_safe_sup}
started: [{pid,<0.353.0>},
{id,alarm_handler},
{mfargs,{alarm_handler,start_link,[]}},
{restart_type,permanent},
{shutdown,2000},
{child_type,worker}]
=PROGRESS REPORT==== 10-Jul-2017::18:04:38 ===
supervisor: {local,sasl_sup}
started: [{pid,<0.352.0>},
{id,sasl_safe_sup},
{mfargs,
{supervisor,start_link,
[{local,sasl_safe_sup},sasl,safe]}},
{restart_type,permanent},
{shutdown,infinity},
{child_type,supervisor}]
=PROGRESS REPORT==== 10-Jul-2017::18:04:38 ===
supervisor: {local,sasl_sup}
started: [{pid,<0.354.0>},
{id,release_handler},
{mfargs,{release_handler,start_link,[]}},
{restart_type,permanent},
{shutdown,2000},
{child_type,worker}]
=PROGRESS REPORT==== 10-Jul-2017::18:04:38 ===
application: sasl
started_at: 'my_gun@127.0.0.1'
=PROGRESS REPORT==== 10-Jul-2017::18:04:38 ===
supervisor: {local,runtime_tools_sup}
started: [{pid,<0.360.0>},
{id,ttb_autostart},
{mfargs,{ttb_autostart,start_link,[]}},
{restart_type,temporary},
{shutdown,3000},
{child_type,worker}]
=PROGRESS REPORT==== 10-Jul-2017::18:04:38 ===
application: runtime_tools
started_at: 'my_gun@127.0.0.1'
Eshell V8.2 (abort with ^G)
(my_gun@127.0.0.1)1> my:ws().
=PROGRESS REPORT==== 10-Jul-2017::18:04:41 ===
supervisor: {local,inet_gethost_native_sup}
started: [{pid,<0.367.0>},{mfa,{inet_gethost_native,init,[[]]}}]
=PROGRESS REPORT==== 10-Jul-2017::18:04:41 ===
supervisor: {local,kernel_safe_sup}
started: [{pid,<0.366.0>},
{id,inet_gethost_native_sup},
{mfargs,{inet_gethost_native,start_link,[]}},
{restart_type,temporary},
{shutdown,1000},
{child_type,worker}]
Upgraded <0.365.0>. Success!
Headers:
[{<<"connection">>,<<"Upgrade">>},
{<<"date">>,<<"Tue, 11 Jul 2017 00:04:40 GMT">>},
{<<"sec-websocket-accept">>,<<"pYv8QeeJfzQgaS/x8flZHyrIexk=">>},
{<<"server">>,<<"Cowboy">>},
{<<"upgrade">>,<<"websocket">>}]
Server received: It's raining!
ok
(my_gun@127.0.0.1)2>
重要的是将案例1和案例2与可选的尾部斜杠相匹配。两者都应该返回一个空的ID（我不确定它是否可以使用RegEx，我的胆量也是如此）。但是如果存在尾随ID，则案例3到6应该匹配。第7例是假的。
我使用以下脚本测试我的RegEx
/test -> should match with ID ""
/test/ -> should match with ID ""
/test/some-id -> should match with ID "some-id"
/test/some-id/ -> should match with ID "some-id/"
/test/some-id/trailing-id-data -> should match with ID "some-id/trailing-id-data"
/test/some-id/trailing-id-data/ -> should match with ID "some-id/trailing-id-data/"
/test-someid -> should not match
首先，我没有期待一个空ID我尝试了几个RegEx，并指定以下一个工作
<?php
$pattern = '...';
$values = [
'/test',
'/test/',
'/test/some-id',
'/test/some-id/',
'/test/some-id/trailing-id-data',
'/test/some-id/trailing-id-data/',
'/test-some-id'
];
foreach ( $values as $value )
{
$matches = [];
var_export( ( bool ) preg_match( $pattern, $value, $matches ) );
echo "\n";
var_export( $matches );
echo "\n\n";
}
现在排在第二位，我正在努力检索空ID。
一般是否可能，如果可能，怎么样？
答案 0 :(得分：2)
此模式将根据需要准确匹配您的字符串：
模式：~^/test(?:$|/)\K.*~仅需81步（与Marcos＆＃39;模式@ 114步相比）
这将匹配/test，如果有任何字符要跟随，则必须以/开头，然后匹配零个或多个字符。 \K表示＆＃34;从此点开始完全匹配＆＃34;，因此您可以避免使用捕获组，只访问preg_match()生成的输出数组中的完整字符串匹配元素。
PHP代码：（PHP Demo）
$values = [
'/test',
'/test/',
'/test/some-id',
'/test/some-id/',
'/test/some-id/trailing-id-data',
'/test/some-id/trailing-id-data/',
'/test-some-id'
];
foreach($values as $v){
echo "$v -> ";
var_export(preg_match("~^/test(?:$|/)\K.*~",$v,$out)?$out:'failed');
echo "\n";
}
输出：
/test -> array (0 => '')
/test/ -> array (0 => '')
/test/some-id -> array (0 => 'some-id')
/test/some-id/ -> array (0 => 'some-id/')
/test/some-id/trailing-id-data -> array (0 => 'some-id/trailing-id-data')
/test/some-id/trailing-id-data/ -> array (0 => 'some-id/trailing-id-data/')
/test-some-id -> 'failed'
答案 1 :(得分：0)